We will solve it using trigonometry formulas:
[tex]\boxed{
\begin{minipage}{5 cm}
{Formulae:} \\ \\
$\bigstar\:\:\sin\theta\:=\:\frac{Opposite}{Hypotenuse} \\ \\
\bigstar\:\:\cos\theta\:=\:\frac{Adjacent}{Hypotenuse} \\ \\
\bigstar\:\:\tan\theta\:=\:\frac{Opposite}{Adjacent}$
\end{minipage}
}[/tex]
[tex]\rule{190pt}{2pt}[/tex]
[tex]\bold{\ttt{Given,}}\\[/tex]
[tex]\sf{Adjacent=40}\\
\sf{Opposite=n}\\
\sf{\theta=74\°[/tex]
[tex]\bold{\ttt{Solution,}}\\[/tex]
[tex]{\tan\theta\:=\:\frac{Opposite}{Adjacent}}}[/tex]
[tex]{\sf{\tan74\:=\:\frac{n}{40}[/tex]
[tex]{\sf{\tan74\:x\:40\:=\:n[/tex]
[tex]{\sf{139.49\:=\:n[/tex]
[tex]{\sf{n\:\approx139.5[/tex]
[tex]\boxed{\sf{n\:=\:139.5}}[/tex]
